Histological assessment of skin grafts stored in amniotic fluid and saline.

We investigated the efficacy of amniotic fluid as a substance in which to store grafts; it is rich in nutrients, proteins, and growth factors, and has well-known antimicrobial features. We compared it with the widely-used and practical saline. Split-thickness grafts 4 × 4 cm were prepared from the back of 20 rats and divided into four groups (n = 5 each). The rolled grafts were wrapped in gauze dampened with saline or amniotic fluid and placed into refrigerators in sterile containers for storage. On days 7, 14, 21, and 28, histological examinations were made. A semiquantitative evaluation of the histological damage to the skin was made by scoring its degree of severity. Compared with saline, histological scores in the grafts stored in amniotic fluid were found to be significantly lower on the 14th, 21st, and 28th days (p values on days 14, 21, and 28; cell swelling: 0.014, 0.006, and 0.005, respectively; nuclear swelling: 0.003, 0.006, and 0.007, respectively; nuclear pleomorphism: 0.004, 0.005, and 0.003, respectively; nuclear haloes: 0.015, 0.005, and 0.005, respectively; nuclear pyknosis: 0.003, 0.005, and 0.003, respectively; dermo-epidermal clefting: 0.005, 0.003, and 0.003, respectively; eosinophilia and mitosis: 0.003, 0.006, and 0.004, respectively; dermal collagen: 0.003, 0.003, and 0.003, respectively). Amniotic fluid maintained preservation better for skin grafts than saline. Comparison with other modern storage media would be beneficial.